Lift mechanism for automobiles

ABSTRACT

A known lift mechanism using a collapsing parallelogram actuated by a hydraulic jack which, when expanded will cause the top frame of the parallelogram to rise, mounts a cross beam having two body-engaging pads at the sides of the parallelogram. Individual wheel support ramps are aligned with each pad, each ramp including a bench supporting the ends of the pad when the parallelogram is collapsed to lower the top frame, so the pads form bridges between the ramps over which the wheels can roll in moving an automobile into position for lifting. The hydraulic jack has a pilot operated check valve unit mounted thereon operable to lock the jack in extended position. The valve unit has a release connection to open its check valve using the pressure fluid line for the jack. It also has a manual unlocking device to open the check valve and lower the parallelogram.

United States Patent [1 1 Clark et a1.

[ LIFT MECHANISM FOR AUTOMOBILES [76] Inventors: Hal J. Clark, 342 N. Greenwood; Victor S. Wells, Box 542, both of Jackson, Wyo. 83001 [22] Filed: Jan. 24, 1973 [21] App]. No.: 326,184

[52] US. Cl. l87/8.72, 187/874 [51] Int. Cl B66f 7/06 [58] Field of Search 187/875, 8.74, 8.72, 8.71,

[4 1 Feb. 11, 1975 Primary Examiner-Richard A. Schacher Assistant Examiner-James L. Rowland Attorney, Agent, or Firm-Wells, St. John & Roberts ABSTRACT A known lift mechanism using a collapsing parallelogram actuated by a hydraulic jack which, when expanded will cause the top frame of the parallelogram to rise, mounts a cross beam having two bodyengaging pads at the sides of the parallelogram. individual wheel support ramps are aligned with each pad. each ramp including a bench supporting the ends of the pad when the parallelogram is collapsed to lower the top frame, so the pads form bridges between the ramps over which the wheels can roll in moving an automobile into position for lifting. The hydraulic jack has a pilot operated check valve unit mounted thereon operable to lock the jack in extended position. The

1 Claim, 7 Drawing Figures PATENTEU 1 3.865.214

SHEET 2 BF 5 FIGQI PATENTED FEB! I I FIG 3 PATENTEB FEB] 1 i975 SHEET 0F 5 kw QM LIFT MECHANISM FOR AUTOMOBILES BACKGROUND OF THE INVENTION The closest prior art of which the applicants are aware is their own prior US. Pat. No. 3,709,330 and the prior patents cited therein. Despite the improvements by these recently patented devices, there is still a need for simplification in the mechanism for bringing an automobile over a lifting device and the lifting of the automobile to allow removal and replacement of its wheels and ready access to the parts underneath the.

body.

OBJECT OF THE INVENTION It is the object of this invention to provide in combination with the lift pads of the known parallelogram type automobile lift mechanism a novel ramp device which utilizes the lift pads as parts of the ramp used in bringing the automobile into position to be raised and lowered by the lift mechanism. It is a further object of this invention to provide this combination in such form that the resulting automobile lifter can be used without any need for pits or other mounting means than a relatively flat surface, and that can be transportedfrom place to place.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 4 is a sectional view on the line 44 of FIG. 4;

FIG. 5 is a longitudinal sectional view through the de- I GENERAL DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings, this invention utilizes the known parallelogram type of automobile lifting mechanism, wherein a lower rectangular frame 1 rests on the ground and an upper rectangular frame 2 is connected thereto by four bars 3, each hinged-to one corner of each frame 1 and 2. A hydraulic jack 4 has its lower end pivoted on an extension 5 of the frame 1. A cross beam 6 is mounted about midway of the upper frame 2 and fixed thereto. The jack 4 has its piston rod 4R pivoted to the side of the beam 6. As shown, if the jack 4 is extended, it pushes the beam 6 and frame 2 endwise and upward to raise whatever is on the beam 6 and frame 2.

The beam carries two lifting pads 7 which as shown are rectangular metal pans 8 with stiff resilient filler units 9 such as foam rubber or foam plastic. These filler extend above the pan rims about two inches or more so they are not compressed enough by the weight of one side ofthe automobile to cause pans 8 to engage the automobile body.

Ramp members 11, 12, 13 and 14 are provided at the ends of the lowered pads 7. These ramp members are filler units 9 serve to cushion the wheels as they move I from ramp member to pad and from pad to ramp member.

The ramp members and the lifting mechanism are combined on a framework F that can be supported as a trailer unit for movement from one location to another. The ramp members 11 and 12 have support legs 16 at their four corners. The ramp members 13 and 14 have like support legs 17 at their four corners. Longitu dinal steel beams 18 and 19 connect the legs 16 and 17 respectively along both sides of the ramp members. End beams 20 connect the four outermost legs 16 and 17 of the two ramp members 11 and 13 to each other at their lower ends. Like beams 21 connect the outermost legs 16 and 17 of the two ramp members 12 and 14 to each other at their lower ends.

The end beam 20 and 21, the two longitudinal beams 18, and the two longitudinal beams 19 are welded together to make the supporting framework F.

A transverse support 22 connects the four longitudinal beams 18 and 19. This support has axles 23 and 24 for wheels 25 and 26. These wheels are used to carry the main load of the device when the supporting framework is connected to a towing vehicle. The pads 7 rest on the benches l5 and aid in the support of the lifting mechanism.

The ramp members 11 through 14 have extension ramp members on them for use when it is not desirable to provide a shallow pit within which the lift mechanism is located. An example is the need for temporary additional lift mechanism to take care of the automobiles at a service station where paving covers the ground in the service station area. Extension ramp members 27 are hinged to the ramp members 12 at their ends remote from the bench 15 thereof. The

members 27 and the ramp members 11 through 14 are connected by hinges 28 strong enough to support the loaded ends of the members 27. At the ends most remote from the ramp members 11 through 14, the members 27 have legs 29 to support them. An angular extension ramp member 30 extends outward from each member 37 to the supporting ground surface.

Each of the ramp members 11, 12, 13 and 14, 27 and 30 have side bars 33 and a middle bar 34 connected together by cross-rods 35. They may also have a reticulated sheet 36 (FIG. 1) such as expanded metal sheet over the rods. When set up for lifting automobiles, the ramp members are extended end to end to carry the automobiles over the ramps until the pads 7 are centered between the front and rear wheels. These pads are adjustable manually on the cross beam 6 so they can be placed directly under the sides of the vehicle body to pick up the body by its side rocker bars.

The lifting and lowering action of the hydraulic jack 4 is controlled by a pilot operated check valve unit 38 which is shown as mounted directly on the lower portion of the jack 4, where it is least likely to be damaged during the use on the mechanism. The valve unit 38 is a pilot operated check valve. This means that oil will flow free in one direction but cannot flow in the opposite direction until the poppet is raised from the seat by some external'means. Valve unit 38 is illustrated in FIG. 7 in an operative lifting condition.

1n the operation of this valve the high pressure of lifting pressure from a pressurized supply tank (not shown) is applied to port 39 (FIG. 7). This forces the poppet 40 off of the valve seat 41 and out of port 42 which is attached to the hydraulic jack 4. Thus the routing of the oil in the lift cycle is: enter through port 39 and exit through port 42.

When the flow of fluid to port 39 is stopped, the poppet 40 is returned to the seat 41 by a very light spring 43 helped by oil escaping by it to return to the supply tank. When the poppet seats, the oil is locked in the hydraulicjack 4 so the vehicle remains in the raised position.

To lower the vehicle, pressure is applied to the pilot port 44 through the small hole to the end. of the slug 45. The O-ring 46 seals the pressure in this cavity. The area of the slug is much greater than the area of the poppet valve 40, therefore slug 45 moves down forcing the poppet off of the seat and letting the oil flow back to the tank. Slug 45 is stopped by a shoulder 47 to assure a clear passage for the oil out of port 39 and to the tank.

We provide a manual override to provide for lowering the vehicle in case of power or mechanical failure. This is accomplished by using a screw 48 to manually move the slug 45 to uncock, the poppet 40 and let the oil escape. There is a jam nut 49 and seal ring (not shown) to prevent leakage and movement of this screw when not being used.

A portable pump and hydraulic reservoir or tank 50 is carried on the folded apparatus (FIG. 6) for travel purposes. It controls valve 38 and hydraulic jack 4.

it is believed that the nature and advantages of our invention will be apparent from the foregoing description. While we have shown and described the preferred form, it is obvious that the details of construction of such parts as the pads, the ramp members and the benches thereon are subject to variation within the scope of our invention which is defined in the following claims. I

We claim: I

1. In an automobile lift assembly:

a supporting rigid framework;

front and rear wheel-supporting ramp means fixed to said framework in a longitudinal orientation at the respective sides thereof and including upwardlyfacing surfaces for receiving the respective wheels of a vehicle positioned on said framework, said front and rear wheel supporting ramp means being longitudinally spaced from one another;

a parallelogram-type lift frame movably mounted to said framework within the longitudinal space between said front and rear wheel supporting ramp means, said lift frame including a pair of horizontal lift pads having upper surfaces longitudinally aligned respectively with said ramp means at each side of the framework, each lift pad spanning the longitudinal space between the front and rear ramp means longitudinally aligned therewith;

power-operated means operably connected between the framework and lift frame for selectively moving the lift frame between a lowered position wherein the upper surfaces of each lift pad serves as a bridge spanning the longitudinal space between the front and rear ramp means longitudinally aligned therewith and a raised or elevated position wherein the lift pads are located elevationally above said lowered position an amount sufficient to release the wheels of a vehicle positioned on said frame- I work from contact with said ramp means by lifting engagement of the vehicle between the wheels; and rigid bench means fixed to said framework beneath said lift frame and intersecting the path of movement of said lift frame for elevationally supporting said lift frame when at said lowered position. 

1. In an automobile lift assembly: a supporting rigid framework; front and rear wheel-supporting ramp means fixed to said framework in a longitudinal orientation at the respective sides thereof and including upwardly-facing surfaces for receiving the respective wheels of a vehicle positioned on said framework, said front and rear wheel supporting ramp means being longitudinally spaced from one another; a parallelogram-type lift frame movably mounted to said framework within the longitudinal space between said front and rear wheel supporting ramp means, said lift frame including a pair of horizontal lift pads having upper surfaces longitudinally aligned respectively with said ramp means at each side of the framework, each lift pad spanning the longitudinal space between the front and rear ramp means longitudinally aligned therewith; power-operated means operably connected between the framework and lift frame for selectively moving the lift frame between a lowered position wherein the upper surfaces of each lift pad serves as a bridge spanning the longitudinal space between the front and rear ramp means longitudinally aligned therewith and a raised or elevated position wherein the lift pads are located elevationally above said lowered position an amount sufficient to release the wheels of a vehicle positioned on said framework from contact with said ramp means by lifting engagement of the vehicle between the wheels; and rigid bench means fixed to said framework beneath said lift frame and intersecting the path of movement of said lift frame for elevationally supporting said lift frame when at said lowered position. 